borderline significantP=0.09
Conversely, patients who underwent adjuvant chemotherapy were compared to those who did not undergo adjuvant chemotherapy, and a significantly decreased risk of death was observed in the BD1 subgroup (HR =0.265, 95% CI: 0.075–0.932, P=0.03), and a borderline significant decreased risk of death was observed in the BD2 subgroup (HR =0.337, 95% CI: 0.096–1.185, P=0.09).